The invention relates to a joint for frame structures with more than two bars connected in one joint. More particularly, the invention relates to a joint wherein the more than two bars are designed as tubes which are inserted through apertures in a metal casing adapted to be filled with a hardening grout, and the end portions of the bars, terminating in the metal casing, have portions which form a positive connection and which are crimped or necked down.
In the type of joint exemplified in British Pat. No. 271,709, the necked-down end portion constitutes a weak point in each bar or tube. The bars must have appropriately large dimensions in order to be able to absorb large tensile forces or bending moments. Relatively large tensile forces acting on the bars can deform the end portion of the bar whereby the positive connection with the grout is lost. Basically, the same problems also exist in the joint taught by Austrian Pat. No. 339,094.